shader_type spatial;
// render_mode blend_mix, depth_draw_always, cull_disabled;
render_mode diffuse_burley, specular_schlick_ggx, blend_mix, depth_draw_always, cull_back, sss_mode_skin;

group_uniforms albedo;
uniform vec4 albedo: source_color = vec4(1.0, 1.0, 1.0, 0.0);
uniform sampler2D albedo_texture: source_color, hint_default_white;

group_uniforms roughness;
uniform float roughness: hint_range(0.0, 1.0) = 0.15;
uniform sampler2D roughness_texture: hint_roughness_r;

group_uniforms refraction;
uniform float refraction: hint_range(-16,16) = 0.5;
uniform sampler2D texture_refraction: filter_linear_mipmap,repeat_enable;
uniform vec4 refraction_texture_channel = vec4(1.0, 0.0, 0.0, 0.0);
uniform sampler2D screen_texture: hint_screen_texture, repeat_disable, filter_linear_mipmap;

group_uniforms normal;
uniform float normal_strength: hint_range(-16.0, 16.0) = 0.0;
uniform sampler2D normal_map: hint_normal;

group_uniforms subsurface_scattering;
uniform float subsurface_scattering_strength: hint_range(0.0, 1.0, 0.01);
uniform sampler2D texture_subsurface_scattering : hint_default_white, filter_linear_mipmap, repeat_enable;

group_uniforms misc;
uniform vec4 edge_color: source_color = vec4(0.0, 0.0, 0.0, 1.0);
uniform float surface_contribution = 0.2;
uniform float specular_contribution = 0.2;
uniform float refraction_contribution = 1.0;
uniform float alpha = 1.0;

group_uniforms uv;
uniform vec3 uv1_scale = vec3(1.0);
uniform vec3 uv1_offset = vec3(0.0);

float SchlickFresnel(float u) {
	float m = 1.0 - u;
	float m2 = m * m;
	return m2 * m2 * m;
}

void vertex() {
	UV=UV*uv1_scale.xy+uv1_offset.xy;
}

void fragment() {
	NORMAL_MAP = texture(normal_map, UV).xyz;
	NORMAL_MAP_DEPTH = normal_strength;

	float VdotN = dot(VIEW, NORMAL);
	float fresnel = clamp(SchlickFresnel(VdotN), 0.0, 1.0);

	vec4 albedo_mix = texture(albedo_texture, UV) * albedo;
	float roughness_mix = texture(roughness_texture, UV).r * roughness;
	float sss_mix = texture(texture_subsurface_scattering, UV).r * subsurface_scattering_strength;

	float a = mix(0.001, 1.0, albedo_mix.a);
	float a_factor_0 = mix(fresnel * edge_color.a, 1.0, a);
	float a_factor_1 = 0.5 * sqrt(a);
	float a_factor_2 = a_factor_0 + a_factor_1;

	ALBEDO = mix(edge_color.rgb * edge_color.a, albedo_mix.rgb * surface_contribution, a);
	ROUGHNESS = roughness_mix;
	SPECULAR = 0.5 * inversesqrt(specular_contribution);
	SSS_STRENGTH = sss_mix;

	vec3 unpacked_normal = NORMAL_MAP;
	unpacked_normal.xy = unpacked_normal.xy * 2.0 - 1.0;
	unpacked_normal.z = sqrt(max(0.0, 1.0 - dot(unpacked_normal.xy, unpacked_normal.xy)));
	vec3 ref_normal = normalize(mix(NORMAL,TANGENT * unpacked_normal.x + BINORMAL * unpacked_normal.y + NORMAL * unpacked_normal.z,NORMAL_MAP_DEPTH));
	vec2 ref_ofs = SCREEN_UV - ref_normal.xy * dot(texture(texture_refraction, UV),refraction_texture_channel) * refraction;
	float ref_amount = 1.0 - albedo_mix.a;
	EMISSION += (textureLod(screen_texture,ref_ofs,ROUGHNESS * 8.0).rgb * ref_amount * EXPOSURE * mix(vec3(mix(0.02, 0.1, a)), albedo_mix.rgb*refraction_contribution, a))/a_factor_2;
	ALBEDO *= 1.0 - ref_amount;
	ALPHA = alpha;
}
